Does this happen when you open a certain application? Does it happen when upon the initial start up? I would suggest you restart the upgrade process using OS 7.0 as it appears as though you are using a leaked OS 7.1 version. There is no telling what could happen on a leaked version.

Does this happen when you open a certain application? Does it happen when upon the initial start up? I would suggest you restart the upgrade process using OS 7.0 as it appears as though you are using a leaked OS 7.1 version. There is no telling what could happen on a leaked version.

it happen after i reboot my phone, because i couldnt sync my t mobile back up contact, just tried to restore with with desktop manager and blackberry protect and i still wont restore my contact . I guess i have to downgrade my phone to 7.0 again sighh...

it happen after i reboot my phone, because i couldnt sync my t mobile back up contact, just tried to restore with with desktop manager and blackberry protect and i still wont restore my contact . I guess i have to downgrade my phone to 7.0 again sighh...

it happen after i reboot my phone, because i couldnt sync my t mobile back up contact, just tried to restore with with desktop manager and blackberry protect and i still wont restore my contact . I guess i have to downgrade my phone to 7.0 again sighh...

I encountered this issue just few days ago..
What I did to make it work again like before was I wiped out my 9900 and then re-install the OS.
You can try some of the Official OS here

After doing the wipe out and re-install, my device works perfectly fine again!

This sometimes happen. I thnk it has someting to do with the update proces. The solution is doing a full wipe using BBSAK prior to update. You can install 7.1.0.342 as I can confirm it is stable on 9900 and 9810 (user myself).
Don't forget to do backup usig DM.

--------->The pursuit of happiness leads to the road of success and fulfillment <---------